Sinks, such as sinks for restrooms or kitchens, typically comprise sink plugs or sink stoppers that are used to facilitate two states, the first stopping water from leaving through the sink outlet and the second allowing it. Sink plugs are during use subject to water, salt, grease, and many other substances disposed of through sinks creating a hostile environment for moving parts. In prior art it is well known to use such moving parts or mechanical means in order to retain a sink plug in the open and/or closed state within a sink outlet. One of the arrangements used in prior art includes a small spring loaded ball retaining the sink plug in predetermined states.
It is further known to counteract movement of a sink plug in a closed and/or an open state through the use of permanent magnets. Such arrangements minimize the use of mechanically moving parts and improve reliability.
It is well known for such arrangements to use a permanent magnet which is attracted to the material of the sink in combination with gravity to enable the opened and closed states. A permanent magnet is arranged within the sink plug which at a closed state is attracted by the sink material meanwhile in an open state only subject to gravity. It is further known to arrange different permanent magnets for the open and closed state where each permanent magnet is located to retain the sink plug in each state.
One problem with the solution for conventional sink plug arrangements comprising moving parts or mechanical means is that the hostile environment tends to affect their performance. This increases the risk of failure and it is a well known problem that moving parts within sink outlets easily get stuck or fails to achieve their purpose.
The failure of mechanical parts affects the ability of the sink plug to stay in an open position or to effectively seal the sink outlet. Similar problems occur in solutions where one permanent magnet is used to attract the material of the sink in order for the sink plug to stay in a closed or open state. The magnet creates only one distinctive state while the other becomes an arbitrary state where the magnet doesn't apply any force on the sink plug. This may cause problems with achieving sufficient sealing properties or causing the sink plug to becoming difficult to attach at each state due to residue or waste in the sink outlet.